78947689 has 2 divisors, whose sum is σ = 78947690. Its totient is φ = 78947688.

The previous prime is 78947683. The next prime is 78947741. The reversal of 78947689 is 98674987.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78907689 + 40000 = 8883^2 + 200^2 .

It is a cyclic number.

It is not a de Polignac number, because 78947689 - 2³ = 78947681 is a prime.

It is not a weakly prime, because it can be changed into another prime (78947681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39473844 + 39473845.

It is an arithmetic number, because the mean of its divisors is an integer number (39473845).

Almost surely, 2^78947689 is an apocalyptic number.

It is an amenable number.

78947689 is a deficient number, since it is larger than the sum of its proper divisors (1).

78947689 is an equidigital number, since it uses as much as digits as its factorization.

78947689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6096384, while the sum is 58.

The square root of 78947689 is about 8885.2512063531. The cubic root of 78947689 is about 428.9893137091.

The spelling of 78947689 in words is "seventy-eight million, nine hundred forty-seven thousand, six hundred eighty-nine".